397 research outputs found

    Intraspecific variation in invertebrate cognition: a review

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    A well-established field of research in vertebrates focuses on the variability of cognitive abilities within species. From mammals to fish, numerous studies have revealed remarkable differences in the cognitive phenotype among individuals, particularly in terms of sex or personality. However, many aspects of the mechanisms, genetics, and selective pressures that underlie individual cognitive variation remain unclear. Surprisingly, intraspecific variability in cognition has received much less attention in invertebrates, despite the increasing evidence of remarkable cognitive abilities in this group and the insights that could be gained from examining simultaneously two distinct taxa, namely vertebrates and invertebrates. In this review, we provide evidence that certain invertebrate species exhibit all the key features of cognitive variation observed in vertebrates, including differences related to sex and personality. In many cases, invertebrate studies have provided insights into the genetic basis, evolvability and response to selection of cognitive variability. Moreover, we highlight evidence for caste differences in eusocial insects, which are linked to task specialisation within the colony. This makes insect eusociality a valuable system for understanding how selection influences cognitive variation. We propose that cognitive variation in invertebrates may be more widespread than currently thought, and that selection may operate in a similar manner on two distantly related cognitive systems (vertebrates and invertebrates). Finally, we suggest that invertebrates hold the potential to serve both as alternative and complementary models to vertebrates, contributing to a deeper understanding of cognitive evolution

    Damping of waves of agitation in starling flocks

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    When a predator attacks a flock of starlings (Sturnus vulgaris), involving thousands of individuals, a typical collective escape response is the so-called agitation wave, consisting of one or more dark bands (pulses) propagating through the flock and moving away from the predator (usually a Peregrine falcon, Falco peregrinus). The mechanism underlying this collective behavior remains debated. A theoretical study has suggested that the individual motion underlying a pulse could be a skitter (in the form of a zigzag), that is copied by nearby neighbors, and causes us to temporarily observe a larger surface of the wing because the bird is banking during turning while zigzagging. It is not known, however, whether pulses during a wave event weaken over time. This is of interest, because whereas during the usual turning by an undisturbed flock the motion is copied completely without weakening, we may expect that pulses dampen during a wave event because individuals that are further away from a predator react less because of reduced fear. In the present paper, we show in empirical data that pulses during a wave event weaken over time. Our computational model, StarDisplay, reveals that this is most likely a consequence of a reduction of the maximum banking angle during the zigzag escape maneuver rather than by a reduced tendency to copy this maneuver with time. The response seems adaptive because of lowered danger at a larger distance to the location of attack

    Utilization of Genetic Counseling after Direct‐to‐Consumer Genetic Testing: Findings from the Impact of Personal Genomics (PGen) Study

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    Direct‐to‐consumer personal genomic testing (DTC‐PGT) results lead some individuals to seek genetic counseling (GC), but little is known about these consumers and why they seek GC services. We analyzed survey data pre‐ and post‐PGT from 1026 23andMe and Pathway Genomics customers. Participants were mostly white (91%), female (60%), and of high socioeconomic status (80% college educated, 43% household income of ≄$100,000). After receiving PGT results, 43 participants (4%) made or planned to schedule an appointment with a genetic counselor; 390 (38%) would have used in‐person GC had it been available. Compared to non‐seekers, GC seekers were younger (mean age of 38 vs 46 years), more frequently had children <18 (26% vs 16%), and were more likely to report previous GC (37% vs 7%) and genetic testing (30% vs 15%). In logistic regression analysis, seeking GC was associated with previous GC use (OR = 6.5, CI = 3.1–13.8), feeling motivated to pursue DTC‐PGT for health reasons (OR = 4.3, CI = 1.8–10.1), fair or poor self‐reported health (OR = 3.1, CI = 1.1–8.3), and self‐reported uncertainty about the results (OR = 1.8, CI = 1.1–2.7). These findings can help GC providers anticipate who might seek GC services and plan for clinical discussions of DTC‐PGT results.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146977/1/jgc41270.pd

    Complex patterns of collective escape in starling flocks under predation

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    Collective behaviour of animals has been a main focus of recent research, yet few empirical studies deal with this issue in the context of predation, a major driver of social complexity in many animal species. When starling (Sturnus vulgaris) flocks are under attack by a raptor, such as a peregrine falcon (Falco peregrinus), they show a great diversity of patterns of collective escape. The corresponding structural complexity concerns rapid variation in density and shape of the flock over time. Here, we present a first step towards unravelling this complexity. We apply a time series analysis to video footage of 182 sequences of hunting by falcons on flocks of thousands of starlings close to two urban roosts during winter. We distinguish several types of collective escape by determining the position and movement of individuals relative to each other (which determines darkness and shape of the flock over time) as well as relative to the predator, namely flash expansion', blackening', wave event', vacuole', cordon' and split'. We show that the specific type of collective escape depends on the collective pattern that precedes it and on the level of threat posed by the raptor. A wave event was most likely to occur when the predator attacked at medium speed. Flash expansion occurred more frequently when the predator approached the flock at faster rather than slower speed and attacked from above rather than from the side or below. Flash expansion was often followed by split, but in many cases, the flock showed resilience by remaining intact. During a hunting sequence, the frequencies of different patterns of collective escape increased when the frequency of attack by the raptor was higher. Despite their complexity, we show that patterns of collective escape depend on the predatory threat, which resembles findings in fish.Significance statementPatterns of collective escape in flocks of starlings have always intrigued laymen and scientists. A detailed analysis of their complex dynamics has been lacking so far, and is the focus of our present study: we analysed video footage of hunting by falcons on flocks of thousands of starlings and show how patterns of collective escape (namely flash expansion, blackening, wave event, vacuole, cordon and split) depend on the preceding pattern and on details of attack. A higher frequency of attack during a hunting sequence resulted in a higher frequency of collective escape events. Flash expansion happened most often when the predator attacks at greater speed. A wave event was most likely when the raptor attacks at medium (rather than high or low) speed. These results provide a first quantitative approach to social complexity in collective avoidance of a predator

    The impact of direct-to-consumer personal genomic testing on perceived risk of breast, prostate, colorectal, and lung cancer: findings from the PGen study

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    Abstract Background Direct access to genomic information has the potential to transform cancer risk counseling. We measured the impact of direct-to-consumer genomic risk information on changes to perceived risk (ΔPR) of breast, prostate, colorectal and lung cancer among personal genomic testing (PGT) customers. We hypothesized that ΔPR would reflect directionality of risk estimates, attenuate with time, and be modified by participant characteristics. Methods Pathway Genomics and 23andMe customers were surveyed prior to receiving PGT results, and 2 weeks and 6 months post-results. For each cancer, PR was measured on a 5-point ordinal scale from “much lower than average” to “much higher than average.” PGT results, based on genotyping of common genetic variants, were dichotomized as elevated or average risk. The relationship between risk estimate and ΔPR was evaluated with linear regression; generalized estimating equations modeled this relationship over time. Results With the exception of lung cancer (for which ΔPR was positive regardless of result), elevated risk results were significantly associated with positive ΔPR, and average risk results with negative ΔPR (e.g., prostate cancer, 2 weeks: least squares-adjusted ΔPR = 0.77 for elevated risk versus −0.21 for average risk; p-valuedifference < 0.0001) among 1154 participants. Large changes were rare: for each cancer, <4 % of participants overall reported a ΔPR of ±3 or more units. Effect modification by age, cancer family history, and baseline interest was observed for breast, colorectal, and lung cancer, respectively. A pattern of decreasing impact on ΔPR over time was consistently observed, but this trend was significant only in the case of colorectal cancer. Conclusions We have quantified the effect on consumer risk perception of returning genetic-based cancer risk information directly to consumers without clinician mediation. Provided via PGT, this information has a measurable but modest effect on perceived cancer risk, and one that is in some cases modified by consumers’ non-genetic risk context. Our observations of modest marginal effect sizes, infrequent extreme changes in perceived risk, and a pattern of diminishing impact with time, suggest that the ability of PGT to effect changes to cancer screening and prevention behaviors may be limited by relatively small changes to perceived risk.http://deepblue.lib.umich.edu/bitstream/2027.42/114396/1/12920_2015_Article_140.pd

    Design, methods, and participant characteristics of the Impact of Personal Genomics (PGen) Study, a prospective cohort study of direct-to-consumer personal genomic testing customers

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    Designed in collaboration with 23andMe and Pathway Genomics, the Impact of Personal Genomics (PGen) Study serves as a model for academic-industry partnership and provides a longitudinal dataset for studying psychosocial, behavioral, and health outcomes related to direct-to-consumer personal genomic testing (PGT). Web-based surveys administered at three time points, and linked to individual-level PGT results, provide data on 1,464 PGT customers, of which 71% completed each follow-up survey and 64% completed all three surveys. The cohort includes 15.7% individuals of non-white ethnicity, and encompasses a range of income, education, and health levels. Over 90% of participants agreed to re-contact for future research. Electronic supplementary material The online version of this article (doi:10.1186/s13073-014-0096-0) contains supplementary material, which is available to authorized users

    Boldness by habituation and social interactions: a model

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    Most studies of animal personality attribute personality to genetic traits. But a recent study by Magnhagen and Staffan (Behav Ecol Sociobiol 57:295–303, 2005) on young perch in small groups showed that boldness, a central personality trait, is also shaped by social interactions and by previous experience. The authors measured boldness by recording the duration that an individual spent near a predator and the speed with which it fed there. They found that duration near the predator increased over time and was higher the higher the average boldness of other group members. In addition, the feeding rate of shy individuals was reduced if other members of the same group were bold. The authors supposed that these behavioral dynamics were caused by genetic differences, social interactions, and habituation to the predator. However, they did not quantify exactly how this could happen. In the present study, we therefore use an agent-based model to investigate whether these three factors may explain the empirical findings. We choose an agent-based model because this type of model is especially suited to study the relation between behavior at an individual level and behavioral dynamics at a group level. In our model, individuals were either hiding in vegetation or feeding near a predator, whereby their behavior was affected by habituation and by two social mechanisms: social facilitation to approach the predator and competition over food. We show that even if we start the model with identical individuals, these three mechanisms were sufficient to reproduce the behavioral dynamics of the empirical study, including the consistent differences among individuals. Moreover, if we start the model with individuals that already differ in boldness, the behavioral dynamics produced remained the same. Our results indicate the importance of previous experience and social interactions when studying animal personality empirically

    Incidence, Predictors, and Significance of Abnormal Cardiac Enzyme Rise in Patients Treated With Bypass Surgery in the Arterial Revascularization Therapies Study (ARTS)

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    BACKGROUND: Although it has been suggested that elevation of CK-MB after percutaneous coronary intervention is associated with adverse clinical outcomes, limited data are available in the setting of coronary bypass grafting. The aim of the present study was to determine the incidence, predictors, and prognostic significance of CK-MB elevation following multivessel coronary bypass grafting (CABG). METHODS AND RESULTS: The population comprises 496 patients with multivessel coronary disease assigned to CABG in the Arterial Revascularization Therapies Study (ARTS). CK-MB was prospectively measured at 6, 12, and 18 hours after the procedure. Thirty-day and 1-year clinical follow-up were performed. Abnormal CK-MB elevation occurred in 61.9% of the patients. Patients with increased cardiac-enzyme levels after CABG were at increased risk of both death and repeat myocardial infarction within the first 30 days (P=0.001). CK-MB elevation was also independently related to late adverse outcome (P=0.009, OR=0.64). CONCLUSIONS: Increased concentrations of CK-MB, which are often dismissed as inconsequential in the setting of multivessel CABG, appear to occur very frequently and are associated with a significant increase in both repeat myocardial infarction and death beyond the immediate perioperative period
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